Process and apparatus for making soap powder



Oct. 22, 1929., O. H. WURSTER PROCESS AND APPARATUS FOR MAKING SOAP POWDER Filed Sept. 7, 1923 Gain MM 91/ Patented Oct. 2 2, 1929 UNITED STATES OSCAR H. WUBSTEB, OF CHICAGO, ILLINOIS PROCESS AND APPARATUS I03 MAKING BOAIP POWDER Application filed September 7, 1823. Serial No. 861,361.

This invention relates to an improved process and apparatus for manufacturing soap powder or cleanser and has for its object the provision of such method and apparatus as shall produce a light, fiufiy powder or granular washing material of superior quality, the apparatus being of improved construction, simple to operate, economical and efiicient. The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawing and described in the following specification and in the steps of the process described herein.

In the drawings Figure 1 is a vertical sectional view showing one form of apparatus for carrying out the present invention;

- Fig. 2 is a sectional view of a discharge nozzle forming part of the apparatus;

Fig. 3 is a transverse section of one form of pump adapted for use in connection with the apparatus; and

Fig. 4 is a fragmentary detail of the pump shown in Fig. 3.

In the manufacture of fiufi'y or aerated soap powder, powdered soap or washing powder, according to the present invention, the material may comprise a combination or mixture of soap, sodium carbonate or soda ash and water or any combination of these ingredients used for manufacturing washing material. A powder or granulated product is produced which consists, according to the ingredients used, of soap and some moisture or of soap and soda ash or crystalline form of sodium carbonate together with moisture or of sodium carbonate and water. By the methods heretofore attempted the time and labor required make the processes expensive and in most of them the resulting product is comparatively compact and heavy. Where the crystallizing rolls are used the equipment is expensive and must be operated continuously to avoid the expense of intermittent operation of refrigerating equipment. Where a chilling process is used the reduction of temperature retards or stops temporarily the reactions between the various ingredients, which reactions are resumed when the temperature is again raised and may result in in- .jllliy to the product after it has been packed.

the present invention the objections incldent to prior methods are avoided and a superior product is economically secured. The apparatus shown in the drawing comprises a mixing vat 10 to which the material is supplied from suitable vessels 11, 12 and 13, there being an agitator in the vessel 10 operated by a shaft 14. The mixture is discharged through a valve 15 into a tempering tank 16 having a stirring wheel 17 therein, the tank being jacketed as shown at 18, through which a tempering fluid is circulated by means of pipes 19 and 20 to control the temperature of the mixture within the vat 16.

In carrying out the process a temperature approximating 140 degrees F. is maintained in the vat 16, but the temperature will be varied for diflferent mixtures and with the titer or hardness of the fatty acids in the soap being used. From the tempering tank the material is forced through pipes 39 by means of a pump 40 and discharged from a spray nozzle 21. Compressed air is introduced into the spray nozzle 21 by means of an air line 22; the pipes 39 and 22 opening into a mixing chamber 23, Fig. 2, where the material is mixed with the compressed air from the pipe 22. The material is then discharged from the nozzle 21 into the tower 24. A baiile 25 may be interposed in the path of the discharging stream of material from the nozzle 23 to assist in breaking up and disintegrating the stream into fine spray. Near the bottom of the tower are located one or more fans 26 which 35 produce an up current of air within the tower, assisting in cooling the descending particles of material, partially evaporating the water therefrom and preventing impalpable powder from reaching the bottom of cthe tower. It is desirable that the portions of soap powder shall be substantially uniform and free from particles which are too fine. Such particles are sustained on the up current of air until they collect to form granules as a conveyor 27 which conducts the material to filling mechanism fed by hopper 28. The tower may have an opening at the top for the escape of the uprising air or the air may pass through the chamber 29 for collecting dust particles which may arise with the air currents. If desired a fan 30-may be located at the top of the tower to produce an upward suction and this fan may be used in conjunction with the fans 26 or either may be used separately. It has been found by experience that better results are obtained if the material is supplied to the nozzle 21 in a pulsating stream. One reason for the superior results secured by supplying the fluid in a pulsating stream is believed to be that this causes the air to enter the stream at the points of minimum pressure, thus dividing the stream into slugs of liquid which is shot from the nozzles by a series of explosions of the pockets of air behind each slug. This disintegrates the liquid into a line spray more thoroughly than can be done where the liquid is supplied in a continuous stream. This theory is supported by the sound produced by the device in operation and also by the vibration set up as well as by the improved results secured. One form of pump for producing such a pulsating operation is shown in Figs. 3 and 4 in which a revolving cylinder 31 is provided with radially sliding vanes 32 rotating in a casing 33. The cylinder 31. is eccentric relative to the casing 83 so that an opening is left at one side of the cylinder through which the material is forced by means of the vanes 32 which are held outwardly against the inner wall of the casing by means of a cam groove 34 and cam rollers 35, Fig. 4, which travel in the groove 34. It will be understood that other forms of pumps may be used, the one illustrated being shown by way of example. In operation it has been found that a pump of this nature driven at from 100 to 300 revolutions per minute produces good results but of course the number of pulsations may be varied within wide limits and the process is not necessarily confined to a pulsating stream, although it has been found that this form of discharge is advantageous. The walls of the tower 24 may be of canvas supported on a suitable framework, and where this is done any material adhering to the inner faces of the walls may be removed by striking or otherwise agitating the canvas without the necessity of entering the tower. If it is desirable for any purpose to carry out the process in a partial vacuum the walls of the tower may be made of sheet metal or other impervious material. Some of the moisture originally in the mixture evaporates as the sprayed material drops through the tower. This evaporation is facilitated by the current of air entering the bottom of the tower and discharging from the top. As the sprayed particles are small the evaporation of the moisture absorbs sufficient heat as latent heat of evaporation to cause a lowering of the temperature and cooling of particles. This natural refrigerating effect or cooling of the fine particles, together with the evaporation of a certain amount of water causes the material to be in dry form when it reaches the bottom of the tower, that is, a form which feels dry to the touch, although of course water is present in the composition of the powder, which may be as high as forty-five per cent in some cases. The powder, however, is a commercially dry product and ready for introduction into packages when it reaches the bottom of the tower. The material has not been chilled in mass and the chilling is not sufliciently sudden to arrest the chemical reaction, so that there is no resumption of these reactions after the material has been packed.

As an example of one kind of mixture which may be used the following proportions may be mentioned: twenty parts anhydrous soap, forty parts soda ash (sodium carbonate) and forty-six parts water. After this material has passed through the tower a portion of the water will be evaporated so that the resulting product will consist of approximately twenty parts by weightof soap and forty parts sodium carbonate and forty parts water in combination or admixture.

It will be understood of course that the mixture referred to is given only by way of example and that any suitable composition of material may be treated, as for instance, a mixture consisting of soap and water alone to produce a powdered or granulated soap, also a mixture of soda ash and water alone, giving a powdered form of sal soda, washing soda, or washing powder. The material resulting from this process may be readily distinguished from those made by scraping or grinding by the uniformity of the particles. Products produced by the former methods contain particles of varying degrees of fineness down to an impalpable powder and having the usual appearance of a ground product. The aerated powder made by the, present process has a fine granular appearance, and the granules, though fine, are more nearly uniform in size than is the case with particles making up a ground powder or one scraped from a crystallizing cylinder. This is an important distinction since the fine powder present in previous products enters the air during the use of the material, thus not only wasting a portion of the material but rendering the air disagreeable and injurious to the user. It will be understood of course that various other materials besides those mentioned may be used, as for example. glycerine or other materials. besides fatty anhydrides and combined alkali may be left in the soap, also naphtha, silicate of soda, potassium carbonate, inert materials and other salts or compounds may be added to the mixture without afl'ecting the process.

I claim:

1. The process of treating soap solution for the production of powdered soap comprising the steps of mixing a cleansing material with water, maintaining a supply of the mixed materialat approximately 140 degrees Fahrenheit, pumping the material from said supply in a pulsating-stream into a mixing chamber, the rate of.pulsation of said stream being from 400 to 1200 per minute,

introducing compressed air into said mixing chamber, discharging the material from said chamber through a restricted nozzle and against a bafile into a tower, 'and maintaining an up current of air in said tower to cool and solidify the particles of said mixture and to suspend the finer particles to cause them to combine with other particles to produce a substantially uniform granular material.

2; Apparatus for treating soap solution for the production of powdered soap comprising an aerating tower, a nozzle having a mixing chamber therein-for discharging material into said tower, .a receptacle having a temperature controlling jacket thereon, a pulsating pump for supplying material from said receptacle to said nozzle, means for introducing compressed air into said chamber in said nozzle, said chamber having a discharge orifice opening into said tower, and means for producing an up current of air in said tower, the walls of said tower bein com osed of flexible material while the mam bo y of the interior of said tower is open and unobstructed to permit the up current of air to substantially fill said tower and encounter the downwardly directed spray from said nozzle.

3. Apparatus for treating soap solution for the prduction of powdered soap comprising an aerating tower having/substantially.

vertical flexible fabric walls a spray nozzle located near the top of said tower, means for causin there eing an opening in the top of said tower to permit the escape of said air and prevent sald current from producing pressure within said tower to 'force the air through" said walls so that the up rising current sustains the (particles discharged into said tower from sai spray nozzle until said particles adhere to one another to attain sufficient size to fall through said up rising current.

4. The process of treating soap solution for the production of owdered soa prising the steps of mixing the material in a liquid form and discharging the material in a pulsating stream through a spray nozzle, and subjecting the material before it leaves the s ray nozzle to compressed air, thereby permitting the compressed air to enter the pulsated stream of said solution at the points of minimum pressure.

an up current of air in said tower,

5. The process of treatin soap solution for the production of powdere soap comprising the steps of mixing the in redients for said powdered soap in a liquid form, pumping the material in a pulsating stream into a mixing chamber and discharging it therefrom in the form of a spray, and introducing compressed air into said chamber before the discharge of said material from said chamber to admit compressed air to the pulsated stream of soap solution at the points of minimum pressure.

6. The process of treating soap solution for the production of powdered soap comprising the steps of mixing the ingredients for said powdered soap with water, and heating the mixture to form a liquid, pumping the material in a pulsating stream into a mixing chamber, introducing compressed air into said chamber to subject the pulsated stream of said solution to the action of compressed air at the points of minimum pressure, and to aerate and discharge the mixture from said chamber through a s ray nozzle.

7; The process 0 treating soap solution for the production of powdered soap comprising the steps of mixing a cleansing material with water, heating said material, pumping said material in a pulsating stream into a mixing chamber, introducing compressed air into the said chamber to sub ect the pulsated stream of soap solution to the action of compressed air at the points of minimum pressure, discharging the material from said chamber into a tower, and maintaining an upcurrent of air in said tower to cool and solidify the particles of said mixture and to suspend the finer particles of said mixture to cause them to combine with-other particles to produce a substantially uniform granular material.

In testimony whereof I have signed my name to this specification on this 4th day of September, A. D. 1923. I

o OSCAR H. WURSTER.

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